ABSTRACT Groundwater is important in the economic context of the Puebla state, where is located the largest portion of the study area, since it determines the feasibility to increase their economic development. The 80% of groundwater is used in agriculture. The largest proportion of available water in the state is in the Oriental Basin. The extraction in the basin has increased in recent years to incorporate new irrigated areas. Agriculture in the basin is conditioned by the characteristics and physical properties of soil and water quality. In high permeability soils, course texture, the sprinkler is used and in soils with high impermeability, fine texture, flood irrigation is reccomended using beds and furrows. When using these irrigation methods, the chemical and agronomical quality of waters becomes an important factor because it may affect soil and crop. Residual sodium carbonate, saturation index and corrected sodium adsorption ratio were used as indexes. These are best for evaluation of bicarbonate-type waters. The mean pH was 8.7. The average concentration of 492.75 mg L-1 and the bicarbonate sodium character of the groundwater basin are defined by volcanic materials. The ion concentration in waters of deep wells is low, with an average of 244.37 mg L-1, an average of 1.80 mmolc Na+L-1 and 2.16 mmolc HCO3 - L-1. The waters of the upper level (water tables) are high in ion concentration, with an average of 865.31 mg L-1, an average of 7.15 mmolc Na+L-1 and 6.92 mmolc HCO3 - L-1. | RESUMEN El agua subterránea es importante en el contexto económico del estado de Puebla, en donde se ubica la mayor proporción del área de estudio, ya que condiciona la factibilidad de incrementar su desarrollo económico. El 80% del agua subterránea se emplea en la agricultura. La mayor proporción del agua disponible, en el estado, se encuentra en la Cuenca Oriental. La extracción en la cuenca se ha incrementado en los últimos años al incorporar nuevas áreas a la agricultura de riego. La agricultura, en la cuenca, está condicionada por las características y propiedades físicas del suelo y la calidad del agua. En suelos de alta permeabilidad, de textura gruesa, se usa el riego por aspersión y en suelos de alta impermeabilidad, de textura fina, el riego por inundación, usando melgas y surcos. Al recurrir a estos métodos de riego, la calidad química y agronómica del agua se convierte en un factor importante, por los efectos que puede tener sobre el suelo y los cultivos. Se usaron índices como: carbonato de sodio residual, índice de saturación y relación de adsorción de sodio corregida. Estos índices son mejores parámetros para la evaluación de las aguas bicarbonatadas. El valor medio del pH fue de 8.7. La concentración media de 492.75 mg L-1 y el carácter sódico bicarbonatado de las aguas subterráneas, de la cuenca, es definida por los materiales de origen volcánico con las que tienen contacto. Las aguas de los pozos profundos, son de baja concentración iónica, con una media de 244.37 mg L-1, una media de 1.80 molc Na+L-1 y 2.16 mmolc HCO3 - L-1. Las aguas del estrato superior, correspondientes a las capas freáticas, son de alta concentración iónica, con una media de 865.31 mg L-1, una media de 7.15 mmol Na+ L-1 y 6.92 mmolc HCO3 - L-1.

An experiment was conducted to study the effect of dietary electrolytic balance (dEB) and addition of sodium bicarbonate to drinking water on carcass and meat quality of pigs. Sodium bicarbonate was used to adjust dEB to 140, 200 and 280 mEq/kg for T1, T2 and T, respectively. 144 Landrace*Duroc male pigs were allocated at 4 per pen and used until 105 kg liveweight. At the end pigs were kept in the same pens and diets for a week during which sodium bicarbonate rich water was supplied to a half of them. Therefore the experimental design was split in a factorial 2x3 and treated water was administered until slaughter. Forty-eight pigs were selected and sent to the slaughterhouse in order to evaluate the effect of experimental treatments on carcass and meat quality parameters. Enriched water significantly increase urine pH, hot and cold carcass weight and killing-out percentage (P<0.01). However did not affect fat or loin depth, lean meat percentage or chilling losses as well as meat quality parameters. pH of muscles Semimembranosus (SM) or Longissimus thoraccis (LT) measured at 45 min were not affected by dEB. However meat pH measured after 24 h statistically increased in both SM (P<0.01) and LT muscles (P<0.05). Pigs fed with low dEB showed a pH indicating meat with a tendency to become acid (5.5<pH<5.6) whereas meat from pigs of the other 2 groups has good ability to be consumed fresh or transformed. Electrical conductivity of SM muscle also indicated better meat quality of pigs fed medium and high dEB (P<0.05). Drip loss from the meat was also strongly reduced as a consequence of dEB (P<0.02). Meat from pigs fed low dEB lost the double of water than meat from pigs fed medium or high dEB. It can be concluded that dEB supplementation could positively affect meat quality parameters like pH 24h, electrical conductivity or drip losses. All these parameters were improved using finishing diets with a medium (200 mEq/kg) or high dEB (280 mEq/kg). Sodium bicarbonate in drinking water before slaughter did not seem to affect meat quality parameters. Nevertheless, it seems that it could improve carcass weight or killing-out percentage but those results need to be confirmed in other trials.